src/linkgraph/linkgraphschedule.h

   1 /*
   2  * This file is part of OpenTTD.
   3  * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
   4  * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
   5  * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
   6  */
   7
   8 /** @file linkgraphschedule.h Declaration of link graph schedule used for cargo distribution. */
   9
  10 #ifndef LINKGRAPHSCHEDULE_H
  11 #define LINKGRAPHSCHEDULE_H
  12
  13 #include "linkgraph.h"
  14
  15 class LinkGraphJob;
  16
  17 /**
  18  * A handler doing "something" on a link graph component. It must not keep any
  19  * state as it is called concurrently from different threads.
  20  */
  21 class ComponentHandler {
  22 public:
  23         /**
  24          * Destroy the handler. Must be given due to virtual Run.
  25          */
  26         virtual ~ComponentHandler() = default;
  27
  28         /**
  29          * Run the handler. A link graph handler must not read or write any data
  30          * outside the given component as that would create a potential desync.
  31          * @param job Link graph component to run the handler on.
  32          */
  33         virtual void Run(LinkGraphJob &job) const = 0;
  34 };
  35
  36 class LinkGraphSchedule {
  37 private:
  38         LinkGraphSchedule();
  39         ~LinkGraphSchedule();
  40         typedef std::list<LinkGraph *> GraphList;
  41         typedef std::list<LinkGraphJob *> JobList;
  42         friend SaveLoadTable GetLinkGraphScheduleDesc();
  43
  44 protected:
  45         std::array<std::unique_ptr<ComponentHandler>, 6> handlers{}; ///< Handlers to be run for each job.
  46         GraphList schedule;            ///< Queue for new jobs.
  47         JobList running;               ///< Currently running jobs.
  48
  49 public:
  50         /* This is a tick where not much else is happening, so a small lag might go unnoticed. */
  51         static const uint SPAWN_JOIN_TICK = 21; ///< Tick when jobs are spawned or joined every day.
  52         static LinkGraphSchedule instance;
  53
  54         static void Run(LinkGraphJob *job);
  55         static void Clear();
  56
  57         void SpawnNext();
  58         bool IsJoinWithUnfinishedJobDue() const;
  59         void JoinNext();
  60         void SpawnAll();
  61         void ShiftDates(TimerGameEconomy::Date interval);
  62
  63         /**
  64          * Queue a link graph for execution.
  65          * @param lg Link graph to be queued.
  66          */
  67         void Queue(LinkGraph *lg)
  68         {
  69                 assert(LinkGraph::Get(lg->index) == lg);
  70                 this->schedule.push_back(lg);
  71         }
  72
  73         /**
  74          * Remove a link graph from the execution queue.
  75          * @param lg Link graph to be removed.
  76          */
  77         void Unqueue(LinkGraph *lg) { this->schedule.remove(lg); }
  78 };
  79
  80 void StateGameLoop_LinkGraphPauseControl();
  81 void AfterLoad_LinkGraphPauseControl();
  82
  83 #endif /* LINKGRAPHSCHEDULE_H */